Marissa blows up balloons for a party. she decides how big or small to make each balloon. why does the air she blows into each balloon take up all the space inside the balloon?

a. the particles of air move around and slide past one another and take the shape of the balloon.
b. the particles of air have a strong attraction between each other and the balloon.
c. the particles of air move freely, colliding with each other and the sides of the balloon.
d. the particles of air move and increase in size when they have more space in the balloon.

Option C, The particles of air move freely, colliding with each other and the sides of the balloon

Explanation:

The air molecules exert force on the inner surface of the balloon due to which the material of the balloon stretches and it increases in size. If air is blown in large extent, it will exert more force on the balloon material thereby extending it to a larger extent but when air is blown in a smaller amount, the size of the balloon increases by a smaller extent.  

Hence, option C is correct

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.